I just did it for my 2010 Sport Trac. The cost was slightly less than that for the units, but I had to order them online. The local dealer couldn't even get them, which I found odd. The part number that you are looking for is 7L2Z7843432B and can be found here : https://www.tascaparts.com. Cost is about $102 + shipping for both kits.
I took the lock kits and my key to a locksmith and they were able to rekey it no problem (cost was $25). All the required wafers are part of the kit and everything that the locksmith needs to rekey it to your key is included in the package. Pulling the old units from the tonneau cover is REALLY easy, so just plan on doing it yourself. just flip the cover upside down, and pull the 2 nuts off of the release mechanism case, then pull the u clip off of the case and that will release the lock from the cover. Put the new lock in, put the clip back on and then put the 2 nuts back on. You should be able to do each lock in about 5 minutes or so.